Thus, the invention applies to the lubrication of chainsaw chains, as stated above. The invention applies particularly to the lubrication of the saw chain of the harvester chainsaw. On a chainsaw, the saw chain rotates in a continuous loop within the groove in the rim of the guide bar. At the other end of the guide bar is a drive gear wheel, which generates the rotation of the saw chain in the gap in the guide bar.
A frictional, resistant force affecting the movement of the saw chain is caused between the guide bar and the chain, as well as with the drive gear wheel. In order to reduce this frictional force, oil, acting as a lubricant, is fed to the saw chain. However, the rotation speeds of modern chainsaws are very high. As a result, the centrifugal forces are also very high in the saw chain, and consequently the oil is pushed very forcefully outwards from the chain links, causing a very high level of lubricating oil consumption. This leads to high operating costs. In addition, environmental issues have become very important and so the vast amount of oil leaked into the environment, despite the use of environmentally-friendly oils, is in no way a positive aspect.
On the basis of the above considerations, lubricants other than oil have started to be used in the lubrication of saw chains in the field. Recently, grease has come into use as a lubricant. An example of this kind of application is the solution from the US patent application 2010/0147628 A1, in which grease is fed with the aid of a pump. The pump is located far away from the actuator, meaning that the resultant pressurisation delay in the piping slows down lubrication and makes it imprecise. The pump receives an operational signal on the basis of saw activity, i.e. the pump is activated at certain times, depending on the activity of the saw. The solution also uses a timer, which regulates the activation intervals of the pump.
The drawback to the above solution is its complexity, which raises costs. Due to this complexity, the reliability of the device described above is not the best option for especially difficult circumstances.